1. Field of the Invention
The present invention relates to an inkjet printer, and more particularly, to an ink cartridge which can prevent ink from spilling.
2. Description of the Prior Art
A typical inkjet printer has an ink cartridge for supplying ink. For a color inkjet printer, the ink cartridge commonly has three ink chambers for storing red, green and blue ink. When printing a document, the ink stored in different ink chambers will be ejected from the ink cartridge onto the document to form various colors on the document. Moreover, the ink cartridge has an opening above each of the ink chambers so that air inside the ink chamber can be interchanged with air outside the ink chamber.
In an ink chamber, a complex pressure balancing system is required for balancing the fluid pressure since ink within the ink chamber is consumed continually. One way to store the ink includes filling a porous material in the ink chamber and balancing the pressure by using the opening above the ink chamber. U.S. Pat. No. 4,771,295 discloses such an ink chamber. However, the ink chamber has a major drawback. The porous material tends to diverse ink all over the porous material due to capillary action. Therefore, when the ink cartridge is vibrated, the ink absorbed by top portion of the porous material is likely spilled out of the ink cartridge via the opening of the ink chamber, not only spotting the document during a printing process but also mixing up the ink in other ink chambers.
It is therefore an object of the present invention to provide an ink cartridge of an inkjet printer to solve the aforementioned problems.
In accordance with the claimed invention, the ink cartridge includes a housing, an output channel, a porous material and an adhesive layer. The housing has a vertical ink chamber for storing ink and an opening disposed on a top side of the ink chamber for interchanging air inside the ink chamber with air outside the ink chamber. The output channel is connected with a bottom aide of the ink chamber for supplying ink from the ink chamber. The porous material is filled in the ink chamber for absorbing ink within the ink chamber. The adhesive layer is formed at a top end of the porous material for forming a sealed surface on the top end of the porous material.
It is an advantage of the present invention that the ink cartridge has an adhesive layer formed on the top end of the porous material. This prevents spotting of a document during a printing process and mixing up ink in other ink chambers.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment which is illustrated in the various figures and drawings.